Normal•2y ago

Re-subscribing to delegate events on scene change

Hey yall, my app systemetically changes the scene of all clients in a given order. The first time this happens (from scene A->B) it works great. However, after that (B->C etc), my delegate event (IsSceneChangingDidChange) does not fire.

I can also see that the OnRealtimeModelReplaced() method does not run again. I'm not sure how to manually resubscribe to this delegate to listen for model changes when a new scene is loaded. My RealtimeView component this script is attached to is persistent and a singleton.

Here is the method in question:


protected override void OnRealtimeModelReplaced(SceneSyncModel previousModel, SceneSyncModel currentModel)
    {
        
        if (previousModel != null)
        {
            // Unregister from events
            previousModel.isSceneChangingDidChange -= IsSceneChangingDidChange;
        }

        if (currentModel != null)
        {
            if (currentModel.isFreshModel)
            {
                
                currentModel.nextScene = nextScene;
            }

            // Set local variables based on model
            nextScene = model.nextScene;

            currentModel.isSceneChangingDidChange += IsSceneChangingDidChange;
            
        }
    }


protected override void OnRealtimeModelReplaced(SceneSyncModel previousModel, SceneSyncModel currentModel)
    {
        
        if (previousModel != null)
        {
            // Unregister from events
            previousModel.isSceneChangingDidChange -= IsSceneChangingDidChange;
        }

        if (currentModel != null)
        {
            if (currentModel.isFreshModel)
            {
                
                currentModel.nextScene = nextScene;
            }

            // Set local variables based on model
            nextScene = model.nextScene;

            currentModel.isSceneChangingDidChange += IsSceneChangingDidChange;
            
        }
    }

Thanks in advance!

kapa.ai•4/17/24, 9:14 AM

Hi @NeuroGoblin. I'm kapa.ai, your friendly support bot. I will try to answer your question by searching through the knowledge base.

kapa.ai•4/17/24, 9:14 AM

----------------------
The

OnRealtimeModelReplaced()

OnRealtimeModelReplaced()

method is called when a

RealtimeComponent

RealtimeComponent

is first created and successfully connected to the server, or instantly if it's already connected. It provides a copy of the model and if the

RealtimeComponent

RealtimeComponent

was previously mapped to a different model (e.g., when switching rooms), it provides a reference to the previous model to allow your component to unregister from events source (https://normcore.io/documentation/realtime/synchronizing-custom-data#creating-a-realtimecomponent-subclass).

In your case, if

OnRealtimeModelReplaced()

OnRealtimeModelReplaced()

is not being called again when you switch from scene B to C, it might be because the

RealtimeComponent

RealtimeComponent

is not being recreated or reconnected to the server. This could happen if the

RealtimeComponent

RealtimeComponent

is attached to a GameObject that is not destroyed when loading a new scene.

One way to ensure that

OnRealtimeModelReplaced()

OnRealtimeModelReplaced()

is called again is to manually destroy and recreate the

RealtimeComponent

RealtimeComponent

when loading a new scene. However, this might not be the best solution depending on your specific use case.

Another possible solution is to manually call

OnRealtimeModelReplaced()

OnRealtimeModelReplaced()

when a new scene is loaded. You can do this by subscribing to a scene loaded event in Unity and then calling

OnRealtimeModelReplaced()

OnRealtimeModelReplaced()

with the appropriate arguments.

However, please note that these are general suggestions and might not work perfectly in your specific case. It's recommended to thoroughly test any changes to ensure they work as expected.
----------------------
Note: you can ask me a follow up question by @ mentioning me again

----------------------

kapa.ai•4/17/24, 9:14 AM

@196555254496493568 kapa.ai is still learning and improving, please let us know how it did by reacting below

NeuroGoblinOP•4/17/24, 9:16 AM

@Normcore Assistant if I manually call OnRealtimeModelReplaced() on scene load, how can i supply it with the correct parameters of SceneSyncModel previousModel, SceneSyncModel currentMode ?

kapa.ai•4/17/24, 9:16 AM

Let me check the knowledge base for you. One moment!

kapa.ai•4/17/24, 9:17 AM

----------------------
The

OnRealtimeModelReplaced()

OnRealtimeModelReplaced()

method takes two parameters: and . These are instances of your

RealtimeComponent

RealtimeComponent

's model class ( in your case).

The is the model that was previously associated with your

RealtimeComponent

RealtimeComponent

, and is the new model that is now associated with it.

In the context of your application, you would need to keep track of the current and previous models. You could store the current model in a variable every time you create or update it. Then, when you're about to create or update the model again, you can use the stored model as the and the new model as the .

Here's a basic example of how you might do this:

In this example, is a method you would call whenever you want to update the model. You would pass the new model as a parameter to this method.

Please note that this is a simplified example and might not cover all edge cases. You should adapt this to fit the specific needs and structure of your application.
----------------------
Note: you can ask me a follow up question by @ mentioning me again

----------------------

kapa.ai•4/17/24, 9:17 AM

@196555254496493568 kapa.ai is still learning and improving, please let us know how it did by reacting below

NeuroGoblinOP•4/17/24, 10:33 PM

If anyone else has a response That'd be awesome !

Mechabit•4/17/24, 10:43 PM

if this is a persistent model then you don't need to register again on scene change

Mechabit•4/17/24, 10:46 PM

you could try changing the scene change property to an int instead of a bool, that way you can keep triggering it by incrementing the int because by default no message is sent if the model hasn't been changed (for instance changing a true to a true)

NeuroGoblinOP•4/17/24, 11:12 PM

hmm okay that makes sense - alternatively i could make sure the bool is set to false onsceneloaded?

Mechabit•4/17/24, 11:14 PM

you could also set the skip equality check parameter in the model property

Mechabit•4/17/24, 11:16 PM

or you could add a check for scenemanager.active scene against the scene name property to check you are in the same scene

Mechabit•4/17/24, 11:16 PM

good for late joiners

NeuroGoblinOP•4/18/24, 6:05 AM

Thanks @Mechabit - incrementing the int worked well

NeuroGoblinOP•4/18/24, 6:06 AM

for some reason i could init the bool to false but it didn't want to fire delegate changes after that

NeuroGoblinOP•4/18/24, 6:06 AM

even after explicitly toggling true / false

Mechabit•4/18/24, 6:07 AM

odd

Mechabit•4/18/24, 6:07 AM

the int method works more generally if multiple people access it

Michał Wróblewski•4/18/24, 2:22 PM

I've got one questions @NeuroGoblin, why do you require a room with Persistence? Is it (case A) because of scene changes and you need to preserve data when changing scenes or (case B) do you need it stored "forever" for future connections to the room? I'm asking because if it's the case A, I had that in my project - an escape room with 3 chapters and players progression from chapter 1 through 3. I discussed that here and it's better to have a separate Realtime instance connected to a "session room" where all users are connected to it and the connection is continued when scene changes - so .e.g. you can keep voice chat active when scenes change. I'll try to search where I discussed that so you can check how this case matches yours.

NeuroGoblinOP•4/18/24, 11:32 PM

Hey @Michał Wróblewski , thanks for the question - Essentially the setup here is to have an 'Admin' room (and corresponding Realtime component) that persists through all scenes and all clients remain connected to. The purpose of this is to send global events such as synchronised scene changes, notification messages, etc.

As the users progress through the experience, they will then connect to additional rooms where they can see other players' avatars, etc (this part has already been built). I believe my current Admin setup is the same as the last part of your message, where there is a separate instance (AdminRealtime) that persists through all scenes, and then players simply connect to RoomA, RoomB etc as they progress, to sync the showing of avatars, etc.

Michał Wróblewski•4/19/24, 4:37 PM

All good then, it wasn't clear but I felt similar vibes - good choice anyway and good luck